Bug 2320516 (CVE-2024-49874)

Summary: CVE-2024-49874 kernel: i3c: master: svc: Fix use after free vulnerability in svc_i3c_master Driver Due to Race Condition
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Bug Depends On: 2321081    
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Description OSIDB Bzimport 2024-10-21 19:07:19 UTC
In the Linux kernel, the following vulnerability has been resolved:

i3c: master: svc: Fix use after free vulnerability in svc_i3c_master Driver Due to Race Condition

In the svc_i3c_master_probe function, &master->hj_work is bound with
svc_i3c_master_hj_work, &master->ibi_work is bound with
svc_i3c_master_ibi_work. And svc_i3c_master_ibi_work  can start the
hj_work, svc_i3c_master_irq_handler can start the ibi_work.

If we remove the module which will call svc_i3c_master_remove to
make cleanup, it will free master->base through i3c_master_unregister
while the work mentioned above will be used. The sequence of operations
that may lead to a UAF bug is as follows:

CPU0                                         CPU1

                                    | svc_i3c_master_hj_work
svc_i3c_master_remove               |
i3c_master_unregister(&master->base)|
device_unregister(&master->dev)     |
device_release                      |
//free master->base                 |
                                    | i3c_master_do_daa(&master->base)
                                    | //use master->base

Fix it by ensuring that the work is canceled before proceeding with the
cleanup in svc_i3c_master_remove.